The present disclosure relates to a drum unit including a photosensitive drum and an image forming apparatus including the drum unit.
In a conventional electrographic image forming apparatus, an electrostatic latent image is formed on a surface of a charged photosensitive drum, and then the electrostatic latent image is developed by a toner to form a toner image. When the surface of the photosensitive drum is charged as described above, a discharge product may adhere on the surface of the photosensitive drum. If the discharge product absorbs moisture, an electrical resistance of the surface of the photosensitive drum is lowered, and failure called as an image flow may occur.
In order to avoid the occurrence of the image flow, a configuration to heat the photosensitive drum by a heater and to evaporate the moisture adhered on the surface of the photosensitive drum is well known. When such a configuration is applied, in order to heat the photosensitive drum intensively, the heater is preferably installed inside the photosensitive drum.
For example, conventionally, a drum heater, which includes a heating coil arranged on an insulation sheet, is rolled, and the rolled drum heater is inserted in an inside of the photosensitive drum. Flanges are forcefully inserted in both ends of the photosensitive drum, and a terminal for supplying electrical power to the drum heater is mounted on one of the flanges. An electrode always comes into contact with a circumferential face of an electrode plate coupled to the terminal, and the electrical coupling is kept during the rotation of the photosensitive drum.